This invention generally relates to aerial spraying of chemicals including insecticides, fertilizers and the like, and more particularly to guidance of such aerial spraying for more accurate, safe, and cost effective applications
The need for safe application of pesticides is well known by these skilled in the art aware of the specific dangers and requirements for meeting established government standards, as well as the educated public aware of health hazards associated with chemicals use to control pests in our environment. By way of example, government statutes are created to regulate the distribution, sale, and use of pesticides to protect people and the environment from adverse effects. Research and technology continually effects and enhances methods and procedures including the control of pest and vector mosquitoes. The use of global positioning satellites improved aerial application of pesticides with research on droplet spectrums and the ability to predict the ultimate fate of these droplets released has emphasized the need and importance of meteorology and real-time application optimization.
Ground weather and tracking of vehicles is well known as illustrated by way of example with the disclosure of U.S. Pat. No. 6,424,295 for a GPS weather data recording system for use with the applications of chemicals to agricultural fields. Here, a GPS weather data recording system is used to determine a series of positions of a ground vehicle and the velocity of the vehicle as it traverses an agricultural field. The series of positions and velocity trace the ground track across the field while a wind sensor is used to measure wind velocity with respect to the vehicle. As described, during crop dusting, the dispensing vehicle usually a tractor, makes numerous sequential, adjacent passes, dispensing chemicals in a swath across the field in each pass. The tractors driver carefully follows a ground track which ensures that each successive swath over the field is correctly spaced, distance wise, from the previous swath in order to avoid gaps or overlaps in coverage. Should one swath occur too close to a previous swath, the overlap area receives excessive amounts of chemicals that may prove very expensive to the farmer and can damage or render crops unusable. As indicated, wind conditions at the commencement of the dispensing operations can be very different from wind conditions half way through or near the end of dispensing operations and as a result it is important that such conditions be properly monitored for accurately tracking these conditions with respect to the ground vehicle position. It can be appreciated that such problems existing for the ground vehicle are very much magnified when attempting to dispense such chemicals from an aircraft. As illustrated by way further example and with reference to U.S. Pat. No. 5,334,987 for an agricultural aircraft control system using a global positioning system, chemicals are applied to an agricultural field in a variety of flight patterns. An aircraft computer stores surface coordinates of the field to be sprayed. Based on stored information, the computer produces a flight pattern having the desired orientation and generates signals representative of the amount and direction of deviation from a desired flight pattern. Such prescription styled farming control systems are used with various navigational controllers as illustrated with reference to U.S. Pat. No. 6,266,595 for a method and apparatus for prescription application of products to an agricultural field.
In spite of known uses of GPS vehicle location systems, chemical prescription application methods, and monitoring of local weather conditions, there remains a need to safely apply such chemicals in an efficient and cost effective manner. The present invention satisfies this need.
In view of the foregoing background, an invention including a system and method for controlling a prescribed application of chemicals from an aircraft is herein described. One embodiment of the system may include a first weather station positioned at a preselected altitude and a second weather station positioned generally at ground level. A central communications station communicates altitude and ground weather data with the first and second weather stations and provides weather information to an aircraft for an appropriate distribution of chemicals based on real-time weather conditions at ground level and at the aircraft altitude. An aerostat is operable with the first weather station for poisoning it at the preselected altitude. In one embodiment, a winch may be mounted at ground level and operable with a tether attached to the aerostat, preferably a gas filled balloon, for controlling the altitude of the balloon.
The first and second weather stations comprise instruments that may include a magnetometer configured as a directional compass, an anemometer for determining wind speed, a solid state temperature sensor, a solid state sensor for measuring relative humidity, a solid state aneroid pressure transducer for altitude encoding, an RF transmitter employing spread spectrum processing, a two-way RF transceiver, global positioning receiver, and an interfacing microprocessor. The weather data transmitted to the central station for processing may include temperature, relative humidity, altitude, wind speed and direction, data collection time, and data collection date.
A method aspect of the invention may include carrying a first weather station by an aerostat for providing altitude area weather data and tethering the aerostat to a selected aerostat altitude environmentally coupled to a ground target upon which chemicals are to be applied. A second weather station may then be positioned at a ground location environmentally coupled the ground target for providing ground area weather data. An aircraft having chemicals to be distributed may be provided with a flight plan to meet a prescription distribution of the chemicals and the plan may then be based on ground level and aircraft level weather communicated to the aircraft.
In yet another method aspect of the invention, the aerostat may be tethered from an initial altitude to a preselected altitude through intermediate altitudes in between. Altitude and ground area weather data nay then be analyzes at the various altitudes through which the aerostat is moved, and the aircraft altitude may then be changed to a preferred altitude for the chemical distributing based on the altitude and ground area analyzing. Yet further methods include the aircraft communicating with both the first weather station and the second weather station.
Another method aspect of the invention may include carrying a first weather station by an aerostat for providing altitude area weather data, positioning a second weather station at a ground location environmentally coupled the ground target for providing ground area weather data, receiving altitude and ground weather data transmitted from the first and second weather stations at a central communications station, and tethering the aerostat to a first aerostat altitude environmentally coupled to a ground target upon which chemicals are to be applied. Altitude area and ground area weather data may then be transmitted to the central communications station. The aerostat is then tethered at a second aerostat altitude environmentally coupled to a ground target upon which chemicals are to be applied. The tethering and communicating may then be repeated for communicating altitude area and ground area weather data to the aircraft. The aircraft altitude may then be adjusted to the aerostat altitude if appropriate for controlling the distribution of chemicals to the ground target.
The weather data from the altitude and ground positioned weather stations may be synchronized and include temperature, relative humidity, altitude, wind sped and direction, data collection time, and data collection date, and the data may be transmitted at least once every second.